diff options
| author | David Woodhouse | 2015-05-11 14:59:20 +0100 |
|---|---|---|
| committer | David Woodhouse | 2015-05-11 14:59:20 +0100 |
| commit | 4ed6a540fab8ea4388c1703b73ecfed68a2009d1 (patch) | |
| tree | dde73b1a39c9cc68e25480fb889834706f0cec4e /drivers/iommu | |
| parent | b787f68c36d49bb1d9236f403813641efa74a031 (diff) | |
iommu/vt-d: Fix passthrough mode with translation-disabled devices
When we use 'intel_iommu=igfx_off' to disable translation for the
graphics, and when we discover that the BIOS has misconfigured the DMAR
setup for I/OAT, we use a special DUMMY_DEVICE_DOMAIN_INFO value in
dev->archdata.iommu to indicate that translation is disabled.
With passthrough mode, we were attempting to dereference that as a
normal pointer to a struct device_domain_info when setting up an
identity mapping for the affected device.
This fixes the problem by making device_to_iommu() explicitly check for
the special value and indicate that no IOMMU was found to handle the
devices in question.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@vger.kernel.org (which means you can pick up 18436afdc now too)
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 68d43beccb7e..2ffe58969944 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -696,6 +696,11 @@ static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu return &context[devfn]; } +static int iommu_dummy(struct device *dev) +{ + return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO; +} + static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn) { struct dmar_drhd_unit *drhd = NULL; @@ -705,6 +710,9 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf u16 segment = 0; int i; + if (iommu_dummy(dev)) + return NULL; + if (dev_is_pci(dev)) { pdev = to_pci_dev(dev); segment = pci_domain_nr(pdev->bus); @@ -2969,11 +2977,6 @@ static inline struct dmar_domain *get_valid_domain_for_dev(struct device *dev) return __get_valid_domain_for_dev(dev); } -static int iommu_dummy(struct device *dev) -{ - return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO; -} - /* Check if the dev needs to go through non-identity map and unmap process.*/ static int iommu_no_mapping(struct device *dev) { |